RJ45 vs Cat6: A Clear Connector-and-Cable Guide for Your Network

If you’re confused about “RJ45 vs Cat6”, the short answer is that RJ45 is the connector and Cat6 is the cable category. Once you see how they work together in a complete Ethernet link, choosing the right cable and hardware for your network becomes much easier.

In this guide, we’ll explain the connector-versus-cable difference in plain English, show which RJ45 connectors work with which cable categories, and help you decide when Cat5e, Cat6 or Cat6A makes sense for your home, office or 10G projects.

Why people mix up RJ45 and Cat6

People mix up RJ45 and Cat6 because they see the same plug on the end of every “network cable” and assume the plug name and cable name are interchangeable. In reality, RJ45 describes the connector, while Cat5e, Cat6 and Cat6A describe the cable’s performance category.

Most of the time, you’ll see:

• A flexible “Ethernet cable” that has an RJ45 plug on each end.
• A wall outlet or patch panel with an RJ45 jack.
• Online shops and installers casually calling the whole thing “an RJ45 cable”.

It’s no surprise that users end up asking whether they should “buy RJ45 or Cat6” instead of asking the more accurate question: “Which cable category and which RJ45 connectors do I need?”

This article is designed to replace that fuzzy terminology with clear concepts so you can check what you already have installed, and choose the right components for future work.

RJ45 vs Cat6 in plain English: connector vs cable

The key difference is simple: RJ45 is the plug (and jack) design; Cat6 is a type of Ethernet cable. RJ45 defines the shape and pinout of the connector, while Cat6 defines how the copper pairs inside the cable are built and tested.

We’ll look at both sides and then show how they work together in a complete link.

What is an RJ45 connector?

In practical terms, an RJ45 connector is the 8-pin modular plug and jack used for most Ethernet connections. When you click a “network cable” into a switch, router or wall outlet, that click comes from the RJ45 interface.

RJ45 connectors:

• Provide eight metal contacts for four twisted pairs of copper.
• Follow a standard pinout so devices can talk to each other reliably.
• Are used on many cable categories (Cat5e, Cat6, Cat6A and often Cat7 patch leads) as long as the connector is designed for the cable’s dimensions and performance.

When people say “RJ45 port”, they mean the RJ45 jack on a switch, router, wall plate or patch panel.

What is a Cat6 Ethernet cable?

Cat6 is a category of twisted-pair Ethernet cable defined by structured cabling standards. Compared with older Cat5e, it provides:

• Higher bandwidth (typically up to 250 MHz vs 100 MHz for Cat5e).
• Better control of crosstalk with improved construction and sometimes internal separators.
• Support for Gigabit Ethernet up to 100 m and 10GBASE-T at shorter distances (often up to 55 m in typical installations).

Cat6 cables still look like “normal Ethernet cables”, but:

• They may be slightly thicker than Cat5e.
• They usually have “CAT6” printed on the jacket.
• They benefit from connectors and jacks rated for Cat6 performance.

How RJ45 and Cat6 work together in an Ethernet link

At a high level, RJ45 connectors are the standardized interface, and Cat6 is the high-performance twisted-pair cable that plugs into that interface. When you build a channel, you:

1. Use Cat6 cable for the permanent run (in walls, ceilings, cable trays).
2. Terminate it into Cat6-rated RJ45 jacks on patch panels and outlets.
3. Use Cat6 (or Cat5e, depending on design) patch cords with RJ45 plugs to connect devices.

Together, this creates a Cat6 channel that meets the performance you expect.

Here is a simple comparison view to anchor the difference:

Item	Type	What it is / does	Typical bandwidth / speed (illustrative)	Typical use
RJ45 connector	Connector/interface	8-pin modular plug or jack for Ethernet twisted-pair links	N/A (interface; performance depends on components)	Plugs and ports on Ethernet devices & panels
Cat5e Ethernet cable	Cable category	4-pair copper cable rated for basic Gigabit Ethernet	~100 MHz, up to 1G over 100 m	Home/SMB networks, basic office wiring
Cat6 Ethernet cable	Cable category	Improved 4-pair cable with better crosstalk performance	~250 MHz, 1G to 100 m, 10G on shorter distances	Modern office, higher-margin projects
Cat6A Ethernet cable	Cable category	Augmented Cat6 with even better noise control	~500 MHz, 10GBASE-T up to 100 m	High-density, high-speed networks & backbones

So when you are deciding “RJ45 vs Cat6”, you are really deciding:

• Which cable category to use (Cat5e, Cat6, Cat6A), and
• Which RJ45 connectors/jacks are appropriate for that category and environment.

Is RJ45 the same as an Ethernet cable?

No – RJ45 is just the connector, not the entire Ethernet cable. The cable itself is twisted-pair copper (Cat5e, Cat6, Cat6A, etc.), and the RJ45 plug is the standard interface crimped or terminated onto its ends.

You can think of it this way:

• The Ethernet cable is the highway that carries signals.
• The RJ45 plug and jack are the standardized “entry and exit ramps” for devices.

A Cat5e, Cat6 or Cat6A patch lead with RJ45 plugs on both ends is still “an RJ45-terminated Ethernet cable”, not “an RJ45 cable” as a distinct type.

RJ45 connectors and cable categories: what works with what

In practice, many installers and DIY users wonder whether they can use the same RJ45 connectors for Cat5e and Cat6 and what happens if they mix and match. The short answer is that you should match connector rating to cable category whenever you care about performance or certification.

RJ45 connector ratings for Cat5e, Cat6 and Cat6A

RJ45 connectors are usually marketed and tested as Cat5e, Cat6 or Cat6A-rated plugs/jacks. The differences include:

• Internal geometry and contact layout to control crosstalk at higher frequencies.
• Support for different conductor sizes and cable diameters.
• Sometimes shielding and clamping design for shielded cables.

As a rule of thumb:

• A Cat5e plug/jack is designed to meet Cat5e performance when used on Cat5e-dimensioned cable.
• A Cat6 plug/jack supports higher bandwidth and is tested with Cat6-dimensioned cable.
• A Cat6A plug/jack is designed for Cat6A cables and full-distance 10GBASE-T.

That’s why most structured cabling best practices say: choose connectors and jacks rated for the same or higher category than your cable.

Can you mix RJ45 connectors and cable categories?

You can often physically crimp the “wrong” RJ45 plug onto a cable, but the link will behave like the weakest component, not the highest. To keep your design clean:

• Yes, in some cases you can reuse connectors across categories, but
• No, it’s not good practice to mix lower-rated connectors with higher-rated cable if you care about passing Cat6/Cat6A performance.

A simple way to think about it:

• Cat5e plug on Cat5e cable – OK and standards-aligned.
• Cat6 plug on Cat5e cable – works and may give a bit more headroom, but the link is still effectively Cat5e.
• Cat5e plug on Cat6 cable – often physically possible, but the link is limited to Cat5e performance and may fail Cat6 tests.
• Cat6/Cat6A plug on Cat6/Cat6A cable – recommended for Cat6/Cat6A channels.

You can capture this in a quick compatibility matrix:

Cable type ↓ \ Connector type →	Cat5e plug	Cat6 plug	Cat6A plug
Cat5e cable	Recommended	Acceptable, still Cat5e	Overkill, still Cat5e
Cat6 cable	Not recommended	Recommended	Acceptable (Cat6 channel)
Cat6A cable	Avoid	Not recommended	Recommended

For most projects, the safest rule is:

> Match or exceed the cable category with your RJ45 connectors and jacks.

What happens if you crimp Cat6 cable with Cat5e RJ45 plugs?

If you crimp Cat6 cable with Cat5e RJ45 plugs, the link may work but is unlikely to meet Cat6 performance. Typical issues include:

• The link will be limited to Cat5e-level bandwidth, even though you paid for Cat6 cable.
• Cat6 certification tests (for example, using professional test equipment) may fail on crosstalk or return loss.
• At higher speeds or in noisy environments, you may see intermittent errors or unexplained drops.

From a design perspective, that means you’re paying for a Cat6 cable but still delivering Cat5e-level performance. In structured cabling, we normally recommend keeping components consistent:

• Use Cat6-rated connectors and jacks with Cat6 cable.
• If you retrofit terminations, replace plugs with Cat6 ones instead of reusing old Cat5e stock.

Cat5e vs Cat6 vs Cat6A: which is better for your network?

If you’re deciding between Cat5e, Cat6 and Cat6A, the core question is: what speeds and distances do you actually need, now and in the near future? Cat5e is still fine for many applications, but Cat6 and Cat6A offer more headroom and future-proofing.

Performance and distance by cable category

In simplified terms, structured cabling standards and common practice give you roughly:

Cable category	Typical bandwidth	Typical 1G support	Typical 10G support	Common use cases
Cat5e	~100 MHz	1G up to 100 m	Limited / short runs only	Home/SMB networks, basic office wiring
Cat6	~250 MHz	1G up to 100 m	Often up to ~55 m in typical installations	Modern office, higher-density wiring, small servers
Cat6A	~500 MHz	1G up to 100 m	10GBASE-T up to 100 m	High-density office, data rooms, long 10G channels

Key implications:

• For standard Gigabit Ethernet (1G), Cat5e, Cat6 and Cat6A can all handle up to 100 m channels.
• For 10GBASE-T, Cat6 works for shorter distances but Cat6A is the safer choice for full 100 m channels.
• If you know you’ll need 10G over typical office distances, Cat6A is usually worth planning in from the start.

If you want a standards-oriented reference, you can also look at public summaries such as the Category 6 cable reference.

Which cable should you choose for common scenarios?

To make this more concrete, here’s a simple decision view for typical setups:

1. Home internet / basic office with ≤1 Gbps service
   • Choose Cat5e if:
     • You are building short runs and don’t expect to upgrade beyond 1G.
     • Budget is tight and you want something widely available and proven.
   • Choose Cat6 if:
     • You want a bit more margin against interference and potential future upgrades.
     • Cable cost difference is small in your region.
2. Small business office with internal file sharing / VoIP
   • Choose Cat6 as a sensible default:
     • Supports Gigabit to 100 m with better crosstalk performance.
     • Keeps options open for shorter 10G runs (e.g., between racks).
3. New builds or refurbishments where 10G will matter in the next 5–10 years
   • Choose Cat6A for horizontal runs:
     • Gives you full-distance 10GBASE-T capability.
     • Avoids re-cabling costs later.
4. Small server rooms / high-density patching
   • Choose Cat6A for critical backbone and rack-to-rack links.
   • You can still use Cat6 or even Cat5e for short, non-critical connections, but planning Cat6A as the backbone simplifies future upgrades.

In every case, remember that all three categories typically use RJ45 connectors. The choice is not “RJ45 or Cat6” but “which cable category plus appropriately rated RJ45 hardware”.

For broader context on Ethernet cable selection, you can also review our more general Ethernet cable buying guide.

Do higher-category cables help with gaming ping and latency?

For most gamers, switching from Cat5e to Cat6 will not magically improve ping. Latency is dominated by:

• Your internet service and routing path.
• The distance to the game server.
• Congestion on your local and upstream networks.

What does help is:

• Using wired Ethernet instead of Wi-Fi, even Cat5e, to avoid wireless jitter.
• Ensuring cables and connectors are in good condition, not kinked or poorly crimped.

Upgrading from Cat5e to Cat6 can be part of a broader network quality and future-proofing plan, but you should not expect a noticeable ping improvement just from the cable upgrade.

How to tell Cat5e, Cat6 and Cat7 cables (and hardware) apart

Before you plan an upgrade or mix and match connectors, it helps to know what is already installed. The most reliable way is to check printed markings and labels, then use visual cues as a secondary check.

Reading jacket markings and labels

Almost all structured cabling includes category information printed on the cable jacket. To identify your cables:

1. Look along the cable jacket for printed text such as CAT5e, CAT6 or CAT6A.
2. Note other info such as manufacturer name, shielding (UTP/FTP/SFTP) and rating (e.g., riser/plenum).
3. If you can’t see the jacket (for example, it’s inside a wall), check:
   • Labels on patch panels and wall plates.
   • Any documentation from the installation or as-built drawings.

If the jacket says CAT5e, you have Cat5e cable regardless of the connector attached. The same holds for CAT6 and CAT6A.

Visual cues on cable thickness, separators and connectors

Visual cues are helpful but should be treated as secondary indicators:

• Cable thickness: Cat6 and especially Cat6A cables are often thicker than Cat5e because of more separation and better insulation.
• Separators / splines: Many Cat6 and Cat6A designs include a central cross or spline that helps control crosstalk between pairs.
• Connector/jack design: Cat6 and Cat6A jacks and plugs may have slightly different body shapes and strain relief features.

Use these cues like this:

• If a cable looks very thin and has no markings you can find, it’s most likely not Cat6A.
• If a cable is thick and marked with CAT6A or similar, you can treat it as Cat6A.
• When in doubt, don’t guess based solely on appearance – markings or documentation should always win.

When shielded Cat6 cabling and connectors are worth it

Shielded Cat6 cabling (F/UTP, S/FTP, etc.) and shielded RJ45 connectors are useful when:

• Cables run near heavy electrical equipment, motors, fluorescent ballasts or industrial gear.
• You have long parallel runs next to power cables or radio sources.
• Your environment is unusually noisy and you want extra margin.

In typical office or home environments, unshielded twisted pair (UTP) Cat5e/Cat6 with standard RJ45 connectors is usually sufficient. If you do deploy shielded systems:

• Make sure the shielding is properly bonded and grounded according to standards and local electrical codes.
• Use shielded RJ45 connectors and patch panels that are designed to work with the chosen shielded cable.

Quick answers to common RJ45 and Cat6 questions (FAQ)

What is the difference between RJ45 and Cat6?

RJ45 is the connector (plug and jack) used for Ethernet, while Cat6 is a category of twisted-pair cable defined by performance standards. Multiple cable categories, including Cat5e and Cat6, use RJ45 connectors, so the real decision is which cable category you need plus matching RJ45 hardware.

Is RJ45 the same as an Ethernet cable?

No. RJ45 refers to the 8-pin modular connector, not the cable itself. The cable is typically Cat5e, Cat6 or Cat6A twisted-pair Ethernet cable, and RJ45 plugs are crimped or terminated onto its ends.

Can I use the same RJ45 connectors for Cat5, Cat5e and Cat6 cables?

You can sometimes crimp a lower-rated plug onto a higher-rated cable, but the link will behave like the lowest-rated component, not the best one. For Cat6 or Cat6A cabling, we recommend using Cat6 or Cat6A-rated RJ45 connectors and jacks to meet performance and certification requirements.

Which is better for my network: Cat5e or Cat6?

For basic 1G internet and small networks, Cat5e is still adequate. Cat6 is generally better when you want more margin against interference, plan for short 10G runs or expect higher internal traffic and future upgrades. Both usually use RJ45 connectors, so your main choice is cable category, not connector type.

Do Cat5e, Cat6 and Cat6A cables use the same type of RJ45 connector?

They all use the same RJ45 interface, but the connectors themselves are rated for specific categories. A Cat6A-rated RJ45 connector is designed to work with Cat6A cable and preserve Cat6A performance; using a Cat5e plug on Cat6A cable will limit performance to Cat5e levels.

Do I need Cat6 or Cat6A for Gigabit and 10G networks?

For standard Gigabit Ethernet, Cat5e, Cat6 and Cat6A can all support up to 100 m channels. For 10GBASE-T, Cat6 may work over shorter distances, but Cat6A is the recommended choice when you want full-distance 10G support and predictable performance.

How do I identify whether a cable is Cat5e, Cat6 or Cat7?

Start by looking for printed markings on the cable jacket stating CAT5e, CAT6 or CAT7. If the jacket is not accessible, check labels on patch panels, wall plates or installation documentation. Visual cues like cable thickness and internal separators can support your assessment but should not replace the marked category.

Summary and key takeaways for choosing RJ45 and Cat6

The most important takeaway is that RJ45 and Cat6 are not competing options: RJ45 is the connector interface, while Cat5e, Cat6 and Cat6A are cable categories that all use RJ45 connectors. Once you understand that, the real decisions become clearer.

Here are the key points to remember:

• Define your needs in terms of cable category, not just “RJ45”:
  • Cat5e for basic 1G networks,
  • Cat6 as a solid modern default,
  • Cat6A for full-distance 10G runs and long-term future-proofing.
• Match connector ratings to cable categories: use Cat6/Cat6A-rated RJ45 connectors and jacks with Cat6/Cat6A cabling if you want standards-compliant performance.
• Plan for distance and speed together: Cat6 may be enough for short 10G runs, but Cat6A is safer for long channels at 10G.
• Check what you already have by reading jacket markings and labels before mixing components or planning upgrades.
• Use wired Ethernet wisely: it improves stability and throughput versus Wi-Fi, but don’t expect miracles in gaming ping just from upgrading cable categories.

If you’re planning a new installation or upgrade and want manufacturer-level guidance on choosing Cat5e, Cat6 or Cat6A and matching RJ45 components, we recommend talking through your project details with a cabling supplier. Their experience with similar deployments can help you strike the right balance between cost, performance and future-proofing.